ESO Timeline

This timeline shows highlights and important events in the history of ESO. One of ESO’s original aims was to allow the Member States to work together to build and operate advanced astronomical facilities that were beyond the capabilities of any individual country. In particular, it would allow European astronomers to access the parts of the sky best visible from the southern hemisphere, such as the centre of the Milky Way, or our neighbouring galaxies, the Magellanic Clouds.

An excerpt from the preamble to the ESO Convention of 1962 reads "The Governments of the States parties to this convention [...] desirous of jointly creating an observatory equipped with powerful instruments in the Southern Hemisphere and accordingly promoting and organising co-operation in astronomical research [...]".

21 June 1953 — A shared European Observatory is discussed for the first time by a group of astronomers at Leiden, the Netherlands. Immediately thereafter, the subject was further discussed, also in the Netherlands, at the Groningen conference.

26 January 1954 — ESO declaration by leading astronomers from six European countries expressing the wish that a joint European observatory be established in the southern hemisphere.

December 1955 — Site testing begins in South Africa and later in South America, to identify the best location for the ESO observatory.

April 1995 — Site testing for the future Atacama Large Millimeter/submillimeter Array (ALMA) takes place in Chile together with National Radio Astronomy Observatory and National Astronomical Observatory of Japan.

6 April 2004 — After more than 1000 nights of observations at La Silla, spread over 15 years, astronomers determine the motions of more than 14 000 solar-like stars residing in the neighbourhood of the Sun, showing that our home galaxy has led a much more turbulent and chaotic life than previously assumed.

17 August 2004 — Using the VLT, astronomers measure the age of the oldest star known in the Milky Way: 13.2 billion years old. Read more in ESO Press Release eso0425 and in the ESO Press Release eso0106.

1 December 2010 — The first direct measurements of the spectra of exoplanets and their atmospheres are made with the VLT. Read more in the ESO Press Release eso1047 and in the ESO Press Release eso1002.